Fumihiko Horio and colleagues note that past studies have suggested that regular coffee drinking may reduce the risk of type 2 diabetes. The disease affects millions in the United States and is on the rise worldwide. However, little of that evidence comes from studies on lab animals used to do research that cannot be done in humans.

The scientists fed either water or coffee to a group of laboratory mice commonly used to study diabetes. Coffee consumption prevented the development of high-blood sugar and also improved insulin sensitivity in the mice, thereby reducing the risk of diabetes. Coffee also caused a cascade of other beneficial changes in the fatty liver and inflammatory adipocytokines related to a reduced diabetes risk. Additional lab studies showed that caffeine may be “one of the most effective anti-diabetic compounds in coffee,” the scientists say.